United States. Patent Office · Washington, D.C., Govt. Print. Off. · leaf 992
105each of said paths in such a manner as thevolume of sound admitted through one path is increased in the same proportion as thevolume admitted through the other pathis diminished. HO In testimony whereof I have hereunto setmy hand. CHARLES M. HECK. Copies of this patent may be obtained for five… … <j(Jpb<L€^&
Phonograph · Patents
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